Canon LBP 2460 Service Manual - Page 125

CHAPTER 2 E. Paper Jam Detection The following paper sensors are installed to detect the presence of paper and that paper is being fed correctly. • duplexing unit paper sensor (PS21) • switchback paper sensor (PS22) Jams are detected by the CPU on the duplexing driver PCB by determining whether or not paper is at the appropriate sensor at the correct pre-set timing. When the CPU assesses that a jam has occurred, the duplex feeding process is stopped and the DC controller is notified of the jam. Note: Times T1 and T2 indicate the smallest and largest paper sizes respectively. 1. Switchback unit delay jam When the paper has not reached the switchback paper sensor (PS22) in the specified time after the duplexing pick-up process has begun, the CPU assesses that a switchback unit delay jam has occurred. (Unit: Seconds) PRINT PRINT (Unit: Seconds) DUPLEX DEFLECTOR SOLENOID DRIVE signal (/DUPSLD) Jam check Switchback sensor (PS22) Switchback motor (SMT21) 1.5 Normal Backward (CCW) 1.5 Abnormal Figure 2-9-6 2 - 79